Today I tried setting up Volumio on a Futro S740 (installed from thumb drive to SSD). The system does not autodiscover EFI entries on non-removable storage, so I had to install efibootmgr and run sudo efibootmgr --create --disk /dev/sda --part 1 --label "Volumio" --loader '\efi\BOOT\BOOTX64.EFI' --unicode after /usr/local/bin/x86Installer.sh was completed.
It would be terrific it that was included into the install script as that cost me quite a few nerves :)